Conversion from 20 Nautical leagues to Hands

Information about the Nautical league (nlea)

The nautical league is a unit of length equal to three nautical miles, or exactly 5556 metres. It is longer than the land league by about 728 metres, since it is built from the nautical mile of 1852 metres rather than the statute mile.

The unit belonged to an era when it was the practical measure of coastal jurisdiction. The cannon shot rule, articulated in the seventeenth and eighteenth centuries, held that a state's authority extended as far as it could defend from shore, conventionally taken as three nautical miles. That distance became the standard territorial sea limit and was expressed as one marine league. Many older treaties and statutes define maritime boundaries in leagues for this reason.

The three-mile limit held for centuries before eroding through the twentieth. States progressively claimed wider waters, and the United Nations Convention on the Law of the Sea settled the matter in 1982 by establishing a twelve nautical mile territorial sea and a two hundred mile exclusive economic zone. Both figures are stated in nautical miles rather than leagues, and the older unit fell out of legal use.

Charts and pilot books from the age of sail used the league routinely for describing offshore distances and the visibility of landmarks. Reading those sources accurately requires knowing which league is meant, since the same word could refer to a land league, a marine league or a Spanish or Portuguese variant, and the differences are large enough to matter when reconstructing a historical position.

Today the unit has no navigational role. Charts are marked in nautical miles, and distances at sea are quoted the same way. The nautical league appears only in historical and legal texts.

The unit also underlies a familiar figure in visibility calculations. From a height of about three metres above sea level, the horizon lies roughly one nautical league away, which is why the three-mile limit corresponded loosely to what a lookout could see as well as to what a gun could reach.

One nautical league equals 3 nautical miles, 5556 metres, 5.556 kilometres, or about 3.452 statute miles.

Information about the Hand (hh)

The hand is a unit of length equal to exactly four inches, or 101.6 millimetres. It survives in one specialised application: measuring the height of horses and ponies. Almost nowhere else is it still in use.

The measurement is taken from the ground to the withers, the ridge between the shoulder blades where the neck meets the back. The withers are chosen because they are a fixed skeletal point that does not move as the horse raises or lowers its head, so the figure is reproducible in a way that measuring to the top of the head would not be.

Notation is unusual and frequently misread. Heights are written with a decimal point that does not indicate a decimal fraction. A horse of 15.2 hands stands fifteen hands and two inches, which is 62 inches or 157.5 centimetres. Because a hand is four inches, the digit after the point runs only from 0 to 3, and 15.4 is not a valid height. The abbreviation hh, for hands high, is common.

The boundary between a pony and a horse is conventionally set at 14.2 hands, though the exact threshold varies between breed registries and competitive disciplines. Draught breeds such as the Shire commonly exceed 17 hands. The tallest horses on record have stood over 20 hands.

The unit derives from the breadth of a human palm, an origin shared with several ancient measures. Egyptian and Roman systems both used a palm of comparable size. Its standardisation at four inches in England is usually credited to a statute of Henry VIII. The persistence of the hand in equestrian use is largely conservatism, and metric heights in centimetres are now given alongside it in international competition rules.

Measuring accurately is harder than it appears. The horse must stand square on level ground with its head in a natural position, and a purpose-made measuring stick with a spirit level and sliding crossbar is used rather than a tape. Shoeing adds height, so official measurements specify whether the horse is shod, and competition rules that impose height limits require certification by an appointed measurer.

One hand equals 4 inches, 101.6 millimetres, or 0.1016 metres.